bitesize.d(1) USER COMMANDS bitesize.d(1)
NAME
bitesize.d - analyse disk I/O size by process. Uses DTrace.
SYNOPSIS
bitesize.d
DESCRIPTION
This produces a report for the size of disk events caused by processes.
These are the disk events sent by the block I/O driver.
If applications must use the disks, we generally prefer they do so
sequentially with large I/O sizes, or larger "bites".
Since this uses DTrace, only users with root privileges can run this
command.
EXAMPLES
Sample until Ctrl-C is hit then print report,
# bitesize.d
FIELDS
PID process ID
CMD command and argument list
value size in bytes
count number of I/O operations
NOTES
The application may be requesting smaller sized operations, which are
being rounded up to the nearest sector size or UFS block size.
To analyse what the application is requesting, DTraceToolkit programs
such as Proc/fddist may help.
DOCUMENTATION
See the DTraceToolkit for further documentation under the Docs direc-
tory. The DTraceToolkit docs may include full worked examples with ver-
bose descriptions explaining the output.
EXIT
bitesize.d will sample until Ctrl-C is hit.
AUTHOR
Brendan Gregg [Sydney, Australia]
SEE ALSO
iosnoop(1M), seeksize(1M), dtrace(1M)
version 1.00 Jun 15, 2005 bitesize.d(1)
Mac OS X 10.6 - Generated Thu Sep 17 20:07:13 CDT 2009